PB2195: CHARACTERISTICS OF PATIENTS WITH POLYCYTHEMIA VERA: RESULTS FROM A US ELECTRONIC HEALTH RECORDS DATABASE.
Authors: Ronald Hoffman, Nishit Modi, Steffen Koschmieder, Francesco Passamonti, Nancy Reaven, Suneel Gupta, Arturo Molina, Jean-Jacques Kiladjian
Journal: HemaSphere (2023)

Topic: 16. Myeloproliferative neoplasms - Clinical Background: Prevalence of polycythemia vera (PV) is estimated to be 44 to 57 cases per 100,000 persons in the United States (US). Uncontrolled erythrocytosis is a major disease burden, with leukocytosis and thrombocytosis occurring significantly less frequently. Hematocrit (HCT) values above 45% have been associated with increased thrombotic and cardiovascular events (Marchioli et al, 2013). Current treatment options do not consistently maintain hematocrit (HCT) levels <45% in accordance with European Leukemia Net guidelines (2021) and National Comprehensive Cancer Network (NCCN) treatment guidelines (2020). Aims: This study uses electronic health records (EHR) data to describe the baseline characteristics of a cross-section of PV patients who were currently on treatment, to evaluate the frequency of erythrocytosis, thrombocytosis and leukocytosis in these patients, and to characterize the frequency of disease related symptoms. Methods: We conducted a retrospective study using a US EHR database (Optum EHR Market Clarity) which includes linked EHR and medical and prescription claims covering over 70 million US patients. Eligible adult PV patients had ≥2 diagnosis codes between January 1, 2007, and December 31, 2019, with ≥60 days between the first and last diagnosis code in the data period who were identified as currently on treatment. Patients were indexed at the first diagnosis code preceded by a required 1 year of EHR data and ≥1 year of EHR data or death post-index. PV diagnosis was based on ICD-10 and ICD-9 codes which incorporate WHO criteria. Patients were categorized as low- (≤60 y and no history of thrombotic events) or high-risk (>60 y or having experienced thrombotic event). Results: 4,566 patients met diagnostic criteria and were identified as currently on treatment [Table 1]. 45.1% were on phlebotomy and 71.3% were receiving cytoreductive therapy, primarily hydroxyurea. Mean baseline HCT was 44.5%; 49.4% of the cohort had HCT≥45%. Mean baseline HCT in the high- and low-risk groups was 44.0% and 46.5%, respectively, with 46.8% of the high-risk group and 60.9% of the low-risk group having HCT ≥45%. Average baseline red blood cell (RBC) count was 5.0x106/µl and 24.9% of patients had RBC counts >5.8x106/µl. In the high- and low-risk groups, 22.9% and 33.5%, respectively, had RBC count >5.8x106/µl. Average platelet count at baseline was 389x103/µl with 2.3% overall having platelet count ≥1000x103/µl. In the high- and low-risk group, 2.3% and 2.2% of patients, respectively, had baseline platelet count ≥1000x103/µl. Average white blood cell count (WBC) was 11.0 x103/µl; 4.8% had WBC >25x103/µl. In the high- and low-risk group, 5.5% and 1.2% had WBC >25x103/µl, respectively. Approximately 31% of patients reported fatigue and 14% and 12% reporting pruritus and cognitive dysfunction. Summary/Conclusion: Findings from this US EHR database analysis indicate that in PV patients on treatment, erythrocytosis is the primary unmet need. A sizable fraction of PV patients had high HCT ≥45% and ≥50%. In contrast, only 5% of patients exhibited leukocytosis and 2% exhibited thrombocytosis that requires clinical intervention. Marchioli et al. N Engl J Med 2013; 368:22-33Keywords: Erythrocytosis, Thrombocytosis, Polycythemia vera, Hematocrit